The role of vagal integrity in gastrin releasing peptide stimulated gastroenteropancreatic hormone release and gastric acid secretion

Abstract

The role of the vagus nerve in the control of gastrin releasing peptide (GRP) stimulated gastroenteropancreatic hormone release and gastric acid secretion was investigated in four conscious gastric fistula dogs using a technique of bilateral cryogenic vagal blockade. A 90-min infusion of GRP at a dose of 400 pmol X kg-1. h-1 produced significant elevations in plasma levels of gastrin, motilin, GIP, enteroglucagon, insulin, pancreatic glucagon, pancreatic polypeptide and VIP. Vagal blockade reversibly inhibited the rise of plasma PP and significantly blunted the elevation of plasma VIP. However, the GRP stimulated response of the other hormones investigated was not modified by vagal blockade. Similarly, the substantial secretion of gastric acid observed with GRP was not influenced by vagal blockade. Thus GRP acts predominantly via mechanisms which are independent of vagal integrity, findings that are in support of a major role for the local neuromodulation of hormone release and gastric acid secretion.